Semiconductor equipment

Abstract

To impart stable electrical characteristics to semiconductor devices using oxide semiconductors, thereby improving reliability. One of its objectives is to achieve this. [Solution] The semiconductor device comprises an insulating film and a first metallic acid in contact with the insulating film. A metal oxide film, an oxide semiconductor film partially in contact with the first metal oxide film, and an oxide semiconductor film and an electrical The source electrode and drain electrode are directly connected, and a second gold is in contact with the oxide semiconductor film in part. A metal oxide film and a gate insulating film that is in contact with the second metal oxide film on the second metal oxide film. It comprises a film and a gate electrode on a gate insulating film.

Description

[Technical Field]

[0001] This invention relates to semiconductor devices and methods for manufacturing semiconductor devices.

[0002] In this specification, a semiconductor device refers to a device that can function by utilizing semiconductor properties. This term refers to all types of equipment, and includes electro-optical devices, semiconductor circuits, and electronic devices, all of which are semiconductor equipment. [Background technology]

[0003] A technology for constructing transistors using semiconductor thin films formed on a substrate having an insulating surface. This is attracting attention. The transistor is used in integrated circuits (ICs) and image display devices (display devices). It is widely applied in electronic devices. As a semiconductor thin film applicable to transistors, While recon-based semiconductor materials are widely known, oxide semiconductors are attracting attention as another material. It is.

[0004] For example, as the active layer of a transistor, the electron carrier concentration is 10 18 / cm 3 Less than Using amorphous oxides containing indium (In), gallium (Ga), and zinc (Zn) A transistor is disclosed (see Patent Document 1).

[0005] Transistors using oxide semiconductors are different from transistors using amorphous silicon. It has a faster operating speed and is easier to manufacture than transistors using polycrystalline silicon. It is known that the electrical characteristics of such devices are prone to fluctuation and have low reliability. For example, light The transistor's threshold voltage fluctuates before and after the BT test. In contrast, Patent documents 2 and 3 describe the threshold voltage of a transistor using an oxide semiconductor. To suppress the shift, it is provided on at least one surface of the upper or lower surface of the oxide semiconductor layer. A technology has been developed to prevent charge trapping at the interface of an oxide semiconductor layer by using an interface stabilization layer. It is shown. [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Japanese Patent Publication No. 2006-165528 [Patent Document 2] Japanese Patent Publication No. 2010-16347 [Patent Document 3] Japanese Patent Publication No. 2010-16348 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the transistors disclosed in Patent Document 2 or Patent Document 3 have interface stabilization As a layer, a layer having the same properties as the gate insulating layer and the protective layer is used, and the interface with the active layer Because the state cannot be maintained in good condition, the charge at the interface between the active layer and the interface stabilization layer It is difficult to suppress wrap. In particular, when the interface stabilizing layer and the active layer have equivalent band gaps If a charge is present, charge accumulation can easily occur.

[0008] Therefore, transistors using oxide semiconductors still have sufficient reliability. I can't say that.

[0009] In light of these problems, we aim to provide stable electrical properties to semiconductor devices using oxide semiconductors. One of the objectives is to improve reliability. [Means for solving the problem]

[0010] One aspect of the disclosed invention is that an insulating film such as a gate insulating film or a protective insulating film and an oxide semiconductor film as an active layer do not directly contact each other, but a metal oxide film exists between them and contacts these, and the metal oxide film is made of the same components as the oxide semiconductor film in terms of technical concept. That is, one aspect of the disclosed invention has a structure in which an insulating film made of components different from those of the metal oxide film and the oxide semiconductor film, a metal oxide film, and an oxide semiconductor film are laminated. Here, "the same components as the oxide semiconductor film" means including one or more metal elements selected from the constituent elements of the oxide semiconductor film. By having such a laminated structure, it is possible to sufficiently suppress the capture of charges and the like that may occur due to the operation of the semiconductor device at the interface between the above-mentioned insulating film and the oxide semiconductor film. This effect is achieved by making the metal oxide film composed of a material compatible with the oxide semiconductor film exist in a manner of contacting the oxide semiconductor film, so that charges and the like that may occur due to the operation of the semiconductor device are suppressed from being captured at the interface between the oxide semiconductor film and the metal oxide film. Further, by making the insulating film composed of a material that can form a charge capture center at the interface exist in a manner of contacting the metal oxide film, the above-mentioned charges can be captured at the interface between the metal oxide film and the insulating film according to the mechanism. That is, only with the metal oxide film, it becomes difficult to suppress the capture of charges at the interface with the oxide semiconductor film in a situation where a large amount of charges are generated. By providing an insulating film in a manner of contacting the metal oxide film, charges are preferentially captured at the interface between the metal oxide film and the insulating film. 思想とするものである。つまり、開示する発明の一態様は、金属酸化物膜および酸化物半 導体膜とは異なる成分でなる絶縁膜と、金属酸化物膜と、酸化物半導体膜と、が積層され た構造を備えている。ここで、「酸化物半導体膜と同種の成分」とは、酸化物半導体膜の 構成元素から選択される一または複数の金属元素を含むことを意味する。

[0011] このような積層構造を備えることにより、半導体装置の動作などに起因して生じうる電 荷などが、上述の絶縁膜と酸化物半導体膜との界面に捕獲されることを十分に抑制するこ とができるのである。この効果は、酸化物半導体膜と相性の良い材料によって構成された 金属酸化物膜を酸化物半導体膜と接する態様で存在させることで、半導体装置の動作など に起因して生じうる電荷などが酸化物半導体膜と金属酸化物膜との界面に捕獲されること を抑制し、さらに、界面に電荷の捕獲中心が形成されうる材料を用いて構成された絶縁膜 を金属酸化物膜と接する態様で存在させることにより、金属酸化物膜と絶縁膜との界面に 上述の電荷を捕獲させることができるというメカニズムによるものである。

[0012] すなわち、金属酸化物膜のみでは、電荷が多量に生じる状況において酸化物半導体膜と の界面における電荷の捕獲を抑制するのが困難になるところ、金属酸化物膜と接する態様 の絶縁膜を設けることにより、金属酸化物膜と絶縁膜との界面に優先的に電荷を捕獲し、 Since it is possible to suppress charge trapping at the interface between the oxide semiconductor film and the metal oxide film, Yes. Thus, the effect relating to one aspect of the disclosed invention is that the insulating film, the metal oxide film, and the acid This is due to a structure in which an oxide semiconductor film and an oxide semiconductor film are stacked, and the metal oxide film and oxide semiconductor film are stacked. It can be said that this is a different kind of effect from the effect produced by the laminated structure of the conductive film.

[0013] Furthermore, it suppresses charge trapping at the interface of the oxide semiconductor film, and the charge trapping center is located in the oxide. Due to the aforementioned effect of being able to keep it away from the semiconductor film, malfunctions in semiconductor devices can be prevented. This can suppress the noise and improve the reliability of semiconductor devices.

[0014] Furthermore, based on the mechanism described above, it is desirable that the metal oxide film has sufficient thickness. When the metal oxide film is thin, the effect of charges trapped at the interface between the metal oxide film and the insulating film. This is because the thickness can be larger. For example, a metal oxide film is thicker than an oxide semiconductor film. It is preferable to do so.

[0015] Furthermore, the insulating metal oxide film is used for the source electrode and drain electrode, and the oxide semiconductor. Since it is formed in a manner that does not hinder connection with the film, the source electrode or drain electrode and the oxide Compared to the case where a metal oxide film is present between the semiconductor film and the semiconductor film, this prevents an increase in resistance. Therefore, the degradation of the transistor's electrical characteristics can be suppressed.

[0016] Furthermore, in the thin-film formation process of oxide semiconductors, the stoichiometric composition is affected by factors such as an excess or deficiency of oxygen. When deviations occur from the original state, or when hydrogen or water that forms electron donors are mixed in, the electrical conductivity changes. This changes the electrical properties of a transistor using an oxide semiconductor. These factors cause variations in the properties. Therefore, hydrogen, water, hydroxyl groups, or hydrides (hydrogen compounds) Impurities such as (also known as) are intentionally removed from oxide semiconductors, and the impurity removal process is And at the same time, the supply of oxygen, which is the main component material that makes up oxide semiconductors, decreases. This process enhances the purity of the oxide semiconductor film and makes it electrically i-type (intrinsic).

[0017] Type i (intrinsic) oxide semiconductors are created by removing hydrogen, an n-type impurity, from an oxide semiconductor. By increasing the purity to minimize the inclusion of impurities other than the main components of the oxide semiconductor, type i is produced. (Intrinsic) oxide semiconductors, or oxide semiconductors that are very close to type i (intrinsic). be.

[0018] Furthermore, in the process of converting the oxide semiconductor film to type i, the oxide semiconductor film is composed of the same type of components. It is also possible to simultaneously convert the metal oxide film to type i. In one embodiment of the disclosed invention, acid The metal oxide films provided on the upper and lower surfaces of the oxide semiconductor film contain impurities such as water and hydrogen. It is desirable that the metal oxide film has sufficiently reduced and is electrically i-type.

[0019] Transistors with highly purified oxide semiconductor films have threshold voltage and on-current, etc. The electrical characteristics show almost no temperature dependence. Furthermore, the transistor characteristics are affected by photodegradation. The fluctuations are also small.

[0020] One aspect of the disclosed invention is an insulating film and a first metallic acid in contact with the insulating film. A metal oxide film, an oxide semiconductor film partially in contact with the first metal oxide film, and an oxide semiconductor film and an electrical The source electrode and drain electrode are directly connected, and a second gold is in contact with the oxide semiconductor film in part. A metal oxide film and a gate insulating film that is in contact with the second metal oxide film on the second metal oxide film. This is a semiconductor device having a film and a gate electrode on a gate insulating film.

[0021] In the above, the first metal oxide film and the second metal oxide film are oxide semiconductor films. It may be composed of constituent elements. Also, a first metal oxide film and a second metal oxide The energy gap of a material film can sometimes be larger than the energy gap of an oxide semiconductor film. Furthermore, the energy at the lower end of the conduction band of the first metal oxide film and the second metal oxide film is This can be higher than the energy of the lower end of the conduction band of an oxide semiconductor film.

[0022] Furthermore, in the above, the first metal oxide film and the second metal oxide film are gallium oxide. It may be composed of the following: Also, the ratio of the constituent elements of the first metal oxide film and the second gold The ratio of constituent elements in the oxide film may be equal. Also, the insulating film contains silicon oxide. It may be composed of the following. In addition, the gate insulating film may be silicon oxide or hafnium oxide. It may be composed of including.

[0023] Furthermore, in the above, the second metal oxide film covers the source electrode and the drain electrode. Furthermore, it may be provided in contact with the first metal oxide film. Also, the oxide semiconductor film is the first It may be surrounded by a metal oxide film and a second metal oxide film.

[0024] Furthermore, in the above, the side edge of the oxide semiconductor film in the channel length direction and the first metal oxide film The side edges in the channel length direction may coincide. Also, the channel length of the oxide semiconductor film The side edge in the opposite direction and the side edge of the second metal oxide film in the channel length direction may coincide.

[0025] Furthermore, the above includes a gate insulating film and a second insulating film covering the gate electrode. It also has a conductive film beneath the oxide semiconductor film.

[0026] Furthermore, in the above, the transient is determined by the distance between the source electrode and the drain electrode. The channel length L is between 10 nm and 10 μm, for example, 0.1 μm to 0.5 μm. This is possible. Of course, the channel length L may be 1 μm or more. Also, The channel width W can also be set to 10 nm or more. [Effects of the Invention]

[0027] One embodiment of the present invention provides a transistor having stable electrical characteristics.

[0028] Alternatively, according to one embodiment of the present invention, a transistor having good electrical characteristics and high reliability is provided. Semiconductor equipment is provided. [Brief explanation of the drawing]

[0029] [Figure 1] A plan view and a cross-sectional view showing one embodiment of a semiconductor device. [Figure 2] Band diagrams for transistors having oxide semiconductor films and metal oxide films. [Figure 3] A diagram showing one aspect of a semiconductor device. [Figure 4] A diagram illustrating an example of the manufacturing process for a semiconductor device. [Figure 5] A diagram illustrating an example of the manufacturing process for a semiconductor device. [Figure 6] A diagram illustrating one form of semiconductor device. [Figure 7] A diagram illustrating one form of semiconductor device. [Figure 8] A diagram illustrating one form of semiconductor device. [Figure 9]A diagram illustrating one form of semiconductor device. [Figure 10] A diagram showing electronic equipment. [Modes for carrying out the invention]

[0030] The embodiments of the present invention will be described in detail below with reference to the drawings. However, the present invention This is not limited to the description below, and its form and details can be changed in various ways, as is the case for those skilled in the art. This will be easily understood. Furthermore, the present invention shall be interpreted as being limited to the contents of the embodiments described below. It is not something that should be done.

[0031] The ordinal numbers "1st" and "2nd" are used for convenience only and do not necessarily indicate the order of processes or layering. This does not indicate an order. Furthermore, the terms used in this specification do not specify any particular aspect of the invention. This does not indicate a name.

[0032] (Embodiment 1) In this embodiment, one form of a semiconductor device and a method for manufacturing a semiconductor device are shown in Figures 1 to 5. We will explain using this method.

[0033] <Example of semiconductor device configuration> Figure 1 shows an example of a semiconductor device according to one aspect of the disclosed invention, specifically a transistor 110. Plan and cross-sectional views are shown. Here, Figure 1(A) is a plan view, and Figures 1(B) and 1 (C) shows the cross-sectional views of section AB and section CD in Figure 1(A), respectively. Note that in Figure 1(A), to avoid complexity, the components of transistor 110 are shown. Some parts (for example, the second metal oxide film 210) have been omitted.

[0034] The transistor 110 shown in Figure 1 is located on a substrate 200, with an insulating film 202 and a first metal oxide Film 204, oxide semiconductor film 206, source electrode 208a, drain electrode 208b, second The device includes a metal oxide film 210, a gate insulating film 212, and a gate electrode 214.

[0035] In the transistor shown in Figure 1, the second metal oxide film 210 is the source electrode 208a and covers the drain electrode 208b and is in contact with a part of the first metal oxide film 204 It is provided in the same way. Also, in Figure 1, the first metal oxide film 204 and the second metal oxide The physical film 210 is in contact with the oxide semiconductor film 206 in the region where the oxide semiconductor film 206 does not exist. In other words, The oxide semiconductor film 206 is connected to the first metal oxide film 204 and the second metal oxide film 210. We are surrounded.

[0036] Here, the first metal oxide film 204 and the second metal oxide film 210 are oxide semiconductor films It is preferable to use an oxide with the same components as 206. Specifically, an oxide semiconductor film A film made of oxides of one or more metallic elements selected from the constituent elements. The material has good compatibility with the oxide semiconductor film 206, and this can be used with the first metal oxide film 204 and the second gold By using it in the oxide film 210, the interface with the oxide semiconductor film can be kept in good condition. This is because it is possible to use the above-mentioned material as the first metal oxide film 204 or the second metal oxide film By using 210, the interface between the oxide semiconductor film and the metal oxide film in contact with it (here, the The interface between the first metal oxide film 204 and the oxide semiconductor film 206, or the second metal oxide film This can suppress charge trapping at the interface between 210 and the oxide semiconductor film 206. That is the case.

[0037] Furthermore, both the first metal oxide film 204 and the second metal oxide film 210 are oxide semiconductors. Since the film is made of the same components as the film, in the region where the oxide semiconductor film 206 does not exist, In the case where the first metal oxide film 204 and the second metal oxide film 210 are in contact, The adhesion of these can be improved. Also, the constituent elements of the first metal oxide film 204 It is more desirable to make the ratio equal to the ratio of the constituent elements of the second metal oxide film 210.

[0038] Furthermore, since the oxide semiconductor film 206 is used as the active layer, the first metal oxide film 204 The energy gap of the second metal oxide film 210 is the energy of the oxide semiconductor film 206. - It is required to be larger than the gap. Also, the first metal oxide film 204 and the oxide semiconductor Between the body films 206, or between the second metal oxide film 210 and the oxide semiconductor film 206, At a minimum, carriers should not leak out of the oxide semiconductor film 206 at room temperature (20°C). The formation of an energy barrier is required. For example, the first metal oxide film 204 and the second metal The energy between the lower end of the conduction band of the oxide film 210 and the lower end of the conduction band of the oxide semiconductor film 206 The difference, or the upper edge of the valence band of the first metal oxide film 204 or the second metal oxide film 210. Therefore, the energy difference between this point and the upper edge of the valence band of the oxide semiconductor film 206 is 0.5 eV or more. It is desirable that the voltage be 0.7 eV or higher, and more preferably 1.5 eV or lower. It's nice.

[0039] Specifically, for example, an In-Ga-Zn-O based material is used for the oxide semiconductor film 206. In some cases, a material containing gallium oxide is used to form the first metal oxide film 204 and the second metal The oxide film 210 should be formed. Note that gallium oxide and In-Ga-Zn-O based materials When they are brought into contact, the energy barrier is approximately 0.8 eV on the conduction band side and approximately on the valence band side. The voltage becomes 0.9 eV.

[0040] Note that gallium oxide is GaO x It is also written as such, and it means that oxygen is in excess of the stoichiometric ratio. It is preferable to set the value of x to be between 1.4 and 2.0. Moreover, it is preferable to set the value of x to between 1.5 and 1.8. However, gallium oxide The film contains Group 3 elements such as yttrium, Group 4 elements such as hafnium, and aluminum. It contains impurity elements other than hydrogen, such as Group 13 elements, Group 14 elements like silicon, and nitrogen. Therefore, the energy gap of gallium oxide can be widened to improve its insulating properties. The energy gap of a gallium oxide film that does not contain the aforementioned impurities is 4.9 eV, but the energy gap of a gallium oxide film that does not contain the aforementioned impurities is 4.9 eV. For example, by including more than 0 atomic percent but less than or equal to 20 atomic percent, the energy gap The voltage can be amplified to approximately 6 eV.

[0041] Furthermore, from the perspective of reducing the sources of charge generation and trapping centers, water in metal oxide films It is desirable that impurities such as minerals and water are sufficiently reduced. This idea is based on the principle of oxide semiconductors. This approach is similar to the concept of reducing impurities in conductive films.

[0042] Furthermore, the insulating film 202 and the gate insulating film 212 have a first metal oxide film 204 and a second gold By bringing it into contact with the oxide film 210, charge trapping centers can be formed at the interface. It is desirable to use such materials. Such materials are used for the insulating film 202 and the gate insulating film 212. As a result, the charge is transferred to the interface between the insulating film 202 and the first metal oxide film 204, or to the gate insulating film. Because it is trapped at the interface between the edge film 212 and the second metal oxide film 210, the first metal oxide film Charge trapping at the interface between 204 and the oxide semiconductor film 206, or the second metal oxide film 210 This makes it possible to sufficiently suppress charge trapping at the interface of the oxide semiconductor film 206. However, there are many charge trapping centers at the interface between the gate insulating film 212 and the second metal oxide film 210. When multiple transistors are formed, it can actually worsen the transistor characteristics. Compared to the interface between the oxide semiconductor film 206 and the second metal oxide film 210, charge trapping is slightly more pronounced. A degree that allows for easy formation of a center is considered ideal.

[0043] Specifically, the insulating film 202 and gate insulating film 212 contain silicon oxide, silicon nitride, Aluminum oxide, aluminum nitride, or mixtures thereof can be used. The first metal oxide film 204 and the second metal oxide film 210 are made of materials containing gallium oxide. If present, the insulating film 202 and gate insulating film 212 may contain silicon oxide or silicon nitride. It is preferable to use the first metal oxide film 204 and the second metal oxide film 21 Due to the relationship of being tangent to 0, the energy gap of the insulating film 202 and the gate insulating film 212 is the first The energy gap is larger than that of the metal oxide film 204 and the second metal oxide film 210. desirable.

[0044] Furthermore, at the interface between the insulating film 202 and the first metal oxide film 204, or the gate insulating film 21 Since charge trapping centers can be formed at the interface between 2 and the second metal oxide film 210, Therefore, it is not necessary to limit the materials of the insulating film 202 and the gate insulating film 212 to those mentioned above. Also, at the interface between the insulating film 202 and the first metal oxide film 204, or with the gate insulating film 212 A treatment may be performed to form charge trapping centers at the interface with the second metal oxide film 210. Examples of such processes include plasma treatment and elemental doping (such as ion implantation). There is.

[0045] A second insulating film may be provided on transistor 110. In order to electrically connect the drain electrode 208a and the drain electrode 208b to the wiring, insulating film 2 02, first metal oxide film 204, second metal oxide film 210, gate insulating film 212, Openings may be formed in some of these. Furthermore, below the oxide semiconductor film 206, It may also have two gate electrodes. Note that the oxide semiconductor film 206 is processed in an island shape. It is desirable to do so, but it is not necessary to process it into an island shape.

[0046] Figure 2 shows the transistor 110 described above, that is, the insulating film and metallic acid from the gate electrode GE side. Energy in a structure formed by joining oxide films, oxide semiconductor films, metal oxide films, and insulating films. - This is a band diagram (schematic diagram), E F This is the Fermi level of the oxide semiconductor film. In Figure 2, Let's assume an ideal situation where insulating films, metal oxide films, and oxide semiconductor films are all intrinsic. The dielectric film is determined to be silicon oxide (SiO2). x ) (band gap Eg 8eV~9eV) , as a metal oxide film, gallium oxide (GaO x ) (band gap Eg 4.9eV) In-Ga-Zn-O non-single crystal films (bandgap Eg) are used as oxide semiconductor films (OS). The case using 3.15 eV is shown. Note that the vacuum level and conduction of silicon oxide The energy difference at the bottom of the band is 0.95 eV, and the energy difference between the vacuum level of gallium oxide and the energy at the bottom of the conduction band is 0.95 eV. The energy difference is 3.5 eV, and it is the difference between the vacuum level and the conduction band of an In-Ga-Zn-O non-single crystal film. The energy difference at the lower end is 4.3 eV.

[0047] As shown in Figure 2, the gate electrode side (channel side) of the oxide semiconductor film has an oxide semiconductor and Energy barriers of approximately 0.8 eV and 0.95 eV exist at the interface with the metal oxide. Similarly, on the back channel side (opposite the gate electrode) of the oxide semiconductor film, Energy barriers of approximately 0.8 eV and 0.95 eV exist at the interface between the body and the metal oxide. Such an energy barrier exists at the interface between an oxide semiconductor and a metal oxide. As a result, carrier movement is hindered at the interface, and the carriers remain in the oxide semiconductor. It moves through the oxide semiconductor without moving from the body to the metal oxide. As shown in Figure 2, The oxide semiconductor film, metal oxide layer, and insulating layer are defined as such that the oxide semiconductor film is more efficient than the oxide semiconductor. Materials with gradually increasing band gaps (band gap of insulating films compared to metal oxide films) Such beneficial results can be obtained when the two elements (which are larger) are positioned to sandwich each other.

[0048] Figures 3(A) to 3(G) show cross-sections of transistors with a different configuration from transistor 110. The surface structure is shown. Figures 3(A) to 3(G) show a transient according to one aspect of the disclosed invention. The term "T" refers to a top-gate type transistor.

[0049] The transistor 120 shown in Figure 3(A) consists of an insulating film 202, a first metal oxide film 204, Oxide semiconductor film 206, source electrode 208a, drain electrode 208b, second metal oxide In terms of including the film 210, gate insulating film 212, and gate electrode 214, it is the same as transistor 110. It is passing through. The difference between transistor 120 and transistor 110 is the oxide semiconductor film 20 6 is the position where the source electrode 208a and drain electrode 208b are connected. In the lampistor 120, the source electrode 208a and drain are located beneath the oxide semiconductor film 206. The in electrode 208b is in contact. For other components, see transistor 11 in Figure 1. This is the same as 0. For details, please refer to the description in Figure 1.

[0050] The transistor 130 shown in Figure 3(B) includes the above-mentioned components, and is therefore different from the transistor 130 shown in Figure 3(A). It is common to the transistor 120 shown. Transistor 130 and transistor 120 The difference is that the insulating film 202 has a convex shape, and the oxide semiconductor film 206 is a first metal oxide The point is that it is not completely covered by the material film 204 and the second metal oxide film 210. The other components are the same as in Figure 3(A).

[0051] The transistor 140 shown in Figure 3(C) includes the above-mentioned components, as shown in Figure 3(B). It is common to the transistor 130 shown. Transistor 140 and transistor 130 The difference is that the insulating film 202 has a flat shape, while the first metal oxide film 204 has a convex shape. This is the point. Furthermore, if the substrate 200 has the function of an insulating film 202, the insulating film 202 is set It is not necessary to include it. The other components are the same as in Figure 3(B).

[0052] Transistors 150, 160, and 2000 are shown in Figures 3(D) to 3(G). Stat 170 and transistor 180, in that they include the above-mentioned components, are shown in Figure 1, respectively. Transistors 110, 120, and 200 are shown in Figures 3(A) to 3(C). This is common to the Ta130 and Transistor140. The difference lies in the first metal oxide film. Whether 204 or the second metal oxide film 210 is processed in an island-like manner. The components are the same as those in Figures 1, 3(A) through 3(C).

[0053] <Example of the transistor manufacturing process> The following describes the manufacturing process of the transistor shown in Figure 1 or Figure 3(A), using Figures 4 and 5. Let's explain an example.

[0054] <Manufacturing process for transistor 110> An example of the manufacturing process for the transistor 110 shown in Figure 1 is shown using Figures 4(A) to 4(E). This will be explained. Note that the manufacturing process for transistor 150 shown in Figure 3(D) involves oxide semiconductors. Except for processing the first metal oxide film 204, etc., to match the shape of the conductive film 206, The manufacturing process is the same as that for the radiator 110.

[0055] First, an insulating film 202 is formed on the substrate 200, and the first is placed in contact with the insulating film 202. A metal oxide film 204 is formed (see Figure 4(A)).

[0056] There are no major restrictions on the material of the substrate 200, but it should at least be able to withstand subsequent heat treatment. It is necessary that the substrate has heat resistance. For example, glass substrates, ceramic substrates, quartz substrates. Sapphire substrates and the like can be used as substrate 200. Also, silicon and carbon Single-crystal semiconductor substrates such as silicon, polycrystalline semiconductor substrates, and compounds such as silicon germanium It is also possible to apply semiconductor substrates, SOI substrates, etc., and semiconductor elements on these substrates. A substrate 200 may be used with a child attached.

[0057] Furthermore, a flexible substrate may be used as the substrate 200. A transistor is placed on the flexible substrate. If implemented, the transistor may be directly fabricated on a flexible substrate, or it may be fabricated on another substrate. After forming the transistor, it may be peeled off and transferred to a flexible substrate. In order to detach the transistor and transfer it to a flexible substrate, the peeling is required between the transistor and the other substrate. It is good to form an abscission layer.

[0058] The insulating film 202 is brought into contact with the first metal oxide film 204, and at its interface... It is desirable to use a material in which charge trapping centers can be formed. Such a material is used for the insulating film 20 By using method 2, the charge is trapped at the interface between the insulating film 202 and the first metal oxide film 204. Therefore, charge trapping at the interface between the first metal oxide film 204 and the oxide semiconductor film 206 is sufficiently achieved. It becomes possible to suppress it.

[0059] Specifically, the insulating film 202 contains silicon oxide, silicon nitride, aluminum oxide, and nitrogen Aluminum oxides, mixtures thereof, etc., can be used. For example, the first metal oxide film When using a material containing gallium oxide for 204, the insulating film 202 may contain silicon oxide or Silicon nitride is preferred. Also, the relationship in contact with the first metal oxide film 204 Therefore, the energy gap of the insulating film 202 is the energy gap of the first metal oxide film 204. It is preferable that it be larger than the cap.

[0060] Furthermore, charge trapping centers are formed at the interface between the insulating film 202 and the first metal oxide film 204. If possible, there is no need to limit the material of the insulating film 202 to those mentioned above. A charge trapping center is formed at the interface between the insulating film 202 and the first metal oxide film 204. It is also permissible to perform such treatments. Examples of such treatments include plasma treatment and elemental addition treatment. (For example, ion implantation.)

[0061] There are no particular limitations on the method for fabricating the insulating film 202, but for example, plasma CVD or sputtering The insulating film 202 can be fabricated using a film deposition method such as the densitizing method. Reference numeral 2 may be a single-layer or multi-layer structure of insulating film containing the above-mentioned material.

[0062] Furthermore, if the substrate 200 contains the insulating material described above, the substrate 200 It can be treated as insulating film 202. In other words, insulating film 202 referred to here It is also possible to omit this. In this case, the substrate 200 is made of silicon oxide or the like. It would be more desirable if that were the case.

[0063] The first metal oxide film 204 uses an oxide having the same components as the oxide semiconductor film 206. It is desirable to have such materials. Such materials have good compatibility with the oxide semiconductor film 206, and this is the first By using it in the metal oxide film 204, the state of the interface with the oxide semiconductor film is maintained in good condition. This is because it is possible to do so. In other words, by using the above-mentioned material for the first metal oxide film 204, The interface between the oxide semiconductor film and the metal oxide film in contact with it (here, the first metal oxide film 204 This makes it possible to suppress charge trapping at the interface between the oxide semiconductor film 206 and the film. .

[0064] Furthermore, since the oxide semiconductor film 206 is used as the active layer, the first metal oxide film 204 The energy gap of is greater than the energy gap of the oxide semiconductor film 206. It is required. Also, between the first metal oxide film 204 and the oxide semiconductor film 206, there is at least At room temperature (20°C), energy such that carriers do not flow out of the oxide semiconductor film 206 The formation of an energy barrier is required. For example, the lower end of the conduction band of the first metal oxide film 204, The energy difference between the lower end of the conduction band of the oxide semiconductor film 206, or the first metal oxide film The energy difference between the upper end of the valence band of 204 and the upper end of the valence band of the oxide semiconductor film 206 is A voltage of 0.5 eV or higher is desirable, and 0.7 eV or higher is even more desirable. Also, 1. A voltage of 5 eV or less is desirable.

[0065] Furthermore, from the perspective of reducing the sources of charge generation and trapping centers, water in metal oxide films It is desirable that impurities such as minerals and water are sufficiently reduced. This idea is based on the principle of oxide semiconductors. This approach is similar to the concept of reducing impurities in conductive films.

[0066] There are no particular limitations on the method for fabricating the first metal oxide film 204. For example, plasma CVD or The first metal oxide film 204 can be fabricated using a film deposition method such as sputtering. It is possible. Furthermore, in terms of minimizing the inclusion of hydrogen and water, sputtering methods are suitable. Yes, it is. On the other hand, in terms of improving film quality, methods such as plasma CVD are suitable.

[0067] Next, an oxide semiconductor film is formed on the first metal oxide film 204, and the oxide semiconductor film is The material is processed to form island-shaped oxide semiconductor films 206 (see Figure 4(B)).

[0068] It is desirable to fabricate oxide semiconductor films using methods that minimize the inclusion of hydrogen, water, and other contaminants. It can be fabricated using methods such as sputtering. Furthermore, the thickness of the oxide semiconductor film is It is desirable to make it between 3nm and 30nm. If the oxide semiconductor film is made too thick (for example) If the film thickness is 50 nm or more, there is a risk that the transistor will become normally-on. This is for the reason. Furthermore, the insulating film 202, the first metal oxide film 204, and the oxide semiconductor film are, It is preferable to continuously deposit the film without exposing it to the atmosphere.

[0069] As a material used for oxide semiconductor films, the quaternary metal oxide In-Sn-Ga-Z nO-based systems, and ternary metal oxides such as In-Ga-Zn-O and In-Sn-Zn-O systems. In-Al-Zn-O system, Sn-Ga-Zn-O system, Al-Ga-Zn-O system, Sn- Al-Zn-O systems, and binary metal oxides such as In-Zn-O systems, Sn-Zn-O systems, and A l-Zn-O series, Zn-Mg-O series, Sn-Mg-O series, In-Mg-O series, In-Ga -O systems, or single-component metal oxides such as In-O, Sn-O, and Zn-O systems are used. This can be done. Furthermore, SiO2 may be included in the above materials. Here, for example, In-G a-Zn-O type materials are materials containing indium (In), gallium (Ga), and zinc (Zn). This refers to an oxide film, and the composition ratio is not particularly important. Also, In, Ga, and Zn It may also contain elements other than those mentioned above.

[0070] Furthermore, oxide semiconductor films have the chemical formula InMO3(ZnO) m Materials represented by (m>0) A thin film can be made using [a specific material]. Here, M is selected from Ga, Al, Mn, and Co. It indicates one or more metallic elements. For example, as M, Ga, Ga and Al, Ga Materials such as Mn, or Ga and Co can be used.

[0071] In this embodiment, the oxide semiconductor film is used for In-Ga-Zn-O based oxide semiconductor film deposition. It is formed by a sputtering method using a target.

[0072] When using an In-Ga-Zn-O system material as an oxide semiconductor, the target used and For example, the composition ratio is In2O3:Ga2O3:ZnO = 1:1:1 [mol A target for oxide semiconductor film deposition of [ratio] can be used. The composition does not need to be limited to the above. For example, In2O3:Ga2O3:ZnO=1: A target for oxide semiconductor film deposition with a composition ratio of 1:2 [mol ratio] can also be used.

[0073] Furthermore, when using an In-Zn-O based material as an oxide semiconductor, the target used is The composition ratio, expressed as an atomic ratio, is In:Zn = 50:1 to 1:2 (which translates to In2O3 in molar ratio). :ZnO=25:1~1:4), preferably In:Zn=20:1~1:1 (convert to molar ratio) Calculated, In2O3:ZnO = 10:1 to 1:2), and more preferably In:Zn = 15 :1~1.5:1 (converted to a molar ratio of In2O3:ZnO = 15:2~3:4) For example, the target used to form In-Zn-O based oxide semiconductors has an atomic ratio of In When Zn:O = X:Y:Z, let Z > 1.5X + Y.

[0074] The packing density of the oxide target is 90% to 100%, preferably 95% to 99%. The density should be 9% or less. By using an oxide semiconductor film deposition target with a high packing density, film deposition can be performed. This is because the oxide semiconductor film can be made into a dense film.

[0075] The atmosphere for film deposition is either a noble gas atmosphere (typically argon), an oxygen atmosphere, or a rare gas atmosphere. This can be done under a mixed atmosphere of gas and oxygen. Also, hydrogen, water, and hydroxyl are used in oxide semiconductor films. To prevent contamination with hydrogen, hydroxyl groups, hydrides, and other impurities, the product must be sufficiently free of impurities such as hydrogen, water, hydroxyl groups, and hydrides. It is desirable to use an atmosphere with high-purity gas that has been removed.

[0076] For example, an oxide semiconductor film can be formed as follows:

[0077] First, the substrate 200 is held in a film deposition chamber under reduced pressure, and the substrate temperature is raised to 100°C or higher. The temperature should be 600°C or less, preferably 200°C to 400°C. (The substrate 200 is heated.) By performing the film deposition using this method, the concentration of impurities contained in the oxide semiconductor film can be reduced. Furthermore, it can reduce damage to oxide semiconductor films caused by sputtering. That is the case.

[0078] Next, while removing residual moisture in the deposition chamber, impurities such as hydrogen and water are thoroughly removed. A high-purity gas is introduced, and an oxide semiconductor film is deposited on the substrate 200 using the target described above. To remove residual moisture from the deposition chamber, a cryopump and an ion pump are used as exhaust means. It is desirable to use adsorption-type vacuum pumps such as suction pumps and titanium sublimation pumps. Furthermore, the exhaust system may consist of a turbopump with a cold trap added. The deposition chamber, which is evacuated using a cryopump, contains, for example, hydrogen molecules and water (H2O). Compounds containing hydrogen atoms (and more preferably, compounds containing carbon atoms) have been removed. Therefore, the concentration of impurities in the oxide semiconductor film deposited in the deposition chamber can be reduced.

[0079] As an example of film deposition conditions, the distance between the substrate and the target is 100 mm, and the pressure is 0.6 P. a. A DC power supply of 0.5 kW and a film deposition atmosphere of oxygen (oxygen flow rate ratio 100%). This can be done. Furthermore, when using a pulsed DC power supply, the powdery substance generated during film formation (pulse This is preferable because it reduces the amount of surface layer (also called debris) and minimizes variations in film thickness.

[0080] Furthermore, before forming the oxide semiconductor film by sputtering, argon gas is introduced. Reverse sputtering is performed to generate plasma, and the first metal oxide film 204 is deposited on the surface. It is preferable to remove any powdery material (also called particles or debris). Reverse sputtering and This method involves applying a voltage to a substrate and forming plasma near the substrate to modify the substrate surface. In addition, gases such as nitrogen, helium, and oxygen may be used instead of argon.

[0081] The processing of the oxide semiconductor film involves forming a mask of the desired shape on the oxide semiconductor film, and then... This can be done by etching an oxide semiconductor film. The mask described above is a film It can be formed using methods such as trisography, or by inkjet printing. Any method may be used to form the mask. Note that when processing the oxide semiconductor film, the first By also performing the processing of the metal oxide film 204, the transistor shown in Figure 3(D) is produced. 150 can be produced.

[0082] Note that etching of oxide semiconductor films can be done using either dry etching or wet etching. That's fine. Of course, you can also use them in combination.

[0083] Subsequently, it is desirable to perform a heat treatment (first heat treatment) on the oxide semiconductor film. The first heat treatment removes excess hydrogen (including water and hydroxyl groups) from the oxide semiconductor film. This allows for the adjustment of the structure of oxide semiconductor films and the reduction of defect levels in the energy gap. The temperature of the first heat treatment is 250°C or higher and 650°C or lower, preferably 450°C or higher and 600°C or lower. It is below °C. Furthermore, it is preferable that the temperature of the first heat treatment be below the strain point of the substrate.

[0084] Furthermore, this first heat treatment removes excess hydrogen (water and) from the first metal oxide film 204. It is also possible to remove (hydroxyl groups).

[0085] Heat treatment involves, for example, introducing the workpiece into an electric furnace using a resistance heating element and performing the treatment under a nitrogen atmosphere. This can be done under the conditions of 450°C for 1 hour. During this time, the oxide semiconductor film is not exposed to the atmosphere. To prevent contamination with water or hydrogen, take precautions to avoid this.

[0086] Heat treatment devices are not limited to electric furnaces; they also utilize heat conduction or heat radiation from a heated medium such as gas. A device that heats the object to be processed by injection may also be used. For example, LRTA (Lamp R Rapid Thermal Annealing (GRTA) device, GRTA (Gas Rapid Th RTA (Rapid Thermal Annealing) for devices such as thermal annealing equipment. l) A device can be used. The LRTA device uses halogen lamps, metal halide lamps. Xenon arc lamps, carbon arc lamps, high-pressure sodium lamps, high-pressure mercury lamps This device heats the object to be processed by radiating light (electromagnetic waves) from lamps such as lamps. The GRTA apparatus is a device that performs heat treatment using high-temperature gas. The gas used is Argonaut. Noble gases such as nitrates, or inert gases such as nitrogen, that do not react with the material being treated by heat treatment. This is used.

[0087] For example, as a first heat treatment, the object to be treated is placed in a heated inert gas atmosphere, and several After heating for several minutes, a GRTA treatment may be performed in which the workpiece is removed from the inert gas atmosphere. Using GRTA treatment enables high-temperature heat treatment in a short time. Furthermore, it improves the heat resistance of the workpiece. It can be applied even under temperature conditions exceeding the specified temperature. Furthermore, during the process, an inert gas is used, and acid You may switch to a gas containing an element. Perform the first heat treatment in an oxygen-containing atmosphere. This is because it can reduce defect levels in the energy gap caused by oxygen deficiency. ru.

[0088] The inert gas atmosphere can be nitrogen or a noble gas (helium, neon, argon). It is desirable to apply an atmosphere whose main components are (etc.) and which does not contain water, hydrogen, etc. For example, nitrogen, helium, neon, argon, and other noble gases introduced into heat treatment equipment. The purity should be 6N (99.9999%) or higher, preferably 7N (99.99999%) or higher. (That is, the impurity concentration should be 1 ppm or less, preferably 0.1 ppm or less.)

[0089] In any case, the first heat treatment reduces impurities, resulting in a type i (intrinsic) semiconductor or i By forming oxide semiconductor films that are extremely close to type semiconductors, extremely excellent transient properties can be achieved. It is possible to achieve this goal.

[0090] By the way, the heat treatment described above (the first heat treatment) has the effect of removing hydrogen, water, etc. The heat treatment can also be called a dehydration treatment or a dehydrogenation treatment. Alternatively, dehydrogenation treatment may be performed at a later stage, such as after processing an oxide semiconductor film into an island-like structure. It is also possible to carry it out in this way. Furthermore, such dehydration and dehydrogenation treatments are not limited to just one time. You can do it multiple times.

[0091] In this configuration, the oxide semiconductor film is processed into an island shape, and then the first heat treatment is performed. As explained above, the disclosed invention is not limited to this. After the process is complete, the oxide semiconductor film can be processed.

[0092] Next, a source electrode and A conductive film is formed to form drain electrodes (including wiring formed from the same layer). Then, the conductive film is processed to form the source electrode 208a and the drain electrode 208b. (See Figure 4(C)). Note that the end of the source electrode 208a formed here and the drain electrode The distance from the end of 208b determines the channel length L of the transistor. .

[0093] Examples of conductive films used for the source electrode 208a and drain electrode 208b include A A metal film containing an element selected from l, Cr, Cu, Ta, Ti, Mo, W, or the above Metal nitride films containing elements (titanium nitride film, molybdenum nitride film, tungsten nitride film) ) etc. can be used. Also, either the underside or the upper side of a metal film such as Al or Cu. Both sides have high melting point metal films such as Ti, Mo, and W, or metal nitride films of those metals (titanium nitride film). A configuration in which molybdenum nitride film and tungsten nitride film are stacked may also be used.

[0094] Furthermore, the conductive film used for the source electrode 208a and the drain electrode 208b is conductive gold. It may also be formed from a group oxide. Indium oxide (In2O3) is an example of a conductive metal oxide. , tin oxide (SnO2), zinc oxide (ZnO), indium oxide tin alloy (In2O 3-SnO2 (abbreviated as ITO), indium zinc oxide alloy (In2O3-ZnO ) or materials containing silicon oxide can be used.

[0095] The conductive film can be processed by etching using a resist mask. For exposure during the formation of the resist mask used for etching, ultraviolet light, KrF laser light, or ArF laser light are used. Using laser light or similar methods would be beneficial.

[0096] Furthermore, when performing exposure with a channel length L=25nm or less, for example, a few nm to several tens of nm. Using ultra-short wavelengths of m and extremely short ultraviolet light, Exposure during resist mask formation is recommended. Ultraviolet exposure offers high resolution and depth of field. The degree is also large. Therefore, miniaturizing the channel length L of the transistors that are formed later This makes it possible to increase the operating speed of the circuit.

[0097] Furthermore, etching work using a resist mask formed by a so-called multi-gradation mask The process may be carried out. A resist mask formed using a multi-gradation mask has multiple film thicknesses. This results in a certain shape, and the shape can be further deformed by ashing, thus creating different shapes. It can be used in multiple etching processes to create patterns. A multi-gradation mask allows for registration masks that correspond to at least two different patterns. It is possible to form a block. In other words, the process can be simplified.

[0098] Furthermore, during the etching of the conductive film, a portion of the oxide semiconductor film 206 is etched, creating grooves. It may also become an oxide semiconductor film having a recessed portion.

[0099] Subsequently, plasma treatment is performed using a gas such as N2O, N2, or Ar, and then the exposed material is... Adsorbed water and other substances attached to the surface of the oxide semiconductor film may be removed. Plasma treatment is performed. If this occurs, the oxide semiconductor film 206 will not be exposed to the atmosphere immediately after the plasma treatment. It is desirable to form a second metal oxide film 210 that is in contact with the part.

[0100] Next, the source electrode 208a and the drain electrode 208b are covered, and an oxide semiconductor film is formed. A second metal oxide film 210 is formed so as to be in contact with a portion of 206, and then the second metal A gate insulating film 212 is formed so as to be in contact with the oxide film 210 (see Figure 4(D)).

[0101] Since the second metal oxide film 210 is the same as the first metal oxide film 204, details are omitted. To abbreviate.

[0102] The gate insulating film 212 is the same as the insulating film 202. However, the gate insulating film of the transistor Considering its function as a border film, a material with a high dielectric constant, such as hafnium oxide, is used. It is also permissible to bring it into contact with the second metal oxide film 210. Therefore, it remains desirable to use a material in which charge trapping centers can be formed at that interface. There is no ri.

[0103] After the formation of the second metal oxide film 210, or after the formation of the gate insulating film 212, It is desirable to perform the following heat treatment. The temperature of the second heat treatment is preferably between 250°C and 700°C. Or, it is between 450°C and 600°C. Note that the temperature of the second heat treatment is determined after the strain point of the substrate has been reached. It is preferable that the requirements be met.

[0104] The second heat treatment involves nitrogen, oxygen, and ultra-dry air (with a water content of 20 ppm or less, preferably). Air (1 ppm or less, preferably 10 ppb or less), or noble gas (argon, helium) It is fine to carry it out in an atmosphere such as the above, but the atmosphere of nitrogen, oxygen, ultra-dry air, or noble gas, etc. It is preferable that the gas does not contain water, hydrogen, etc. Also, nitrogen and oxygen are introduced into the heat treatment apparatus. , or the purity of the noble gas is 6N (99.9999%) or higher, preferably 7N (99.999%). The impurity concentration should be 99% or higher (i.e., 1 ppm or less, preferably 0.1 ppm or less). This is preferable.

[0105] In the second heat treatment, the oxide semiconductor film 206 and the second metal oxide film 210 are treated It is heated in contact with the material. Therefore, the dehydration (or dehydrogenation) treatment described above reduces the amount of water used. Oxygen, one of the main component materials that make up oxide semiconductors, which may have some potential to be lost, This allows the oxide semiconductor film to be supplied from the second metal oxide film 210 containing the following. This allows for a reduction in charge trapping centers within oxide semiconductor films.

[0106] Furthermore, this heat treatment results in the first metal oxide film 204 or the second metal oxide film 21 Impurities in the solution are also removed simultaneously, potentially resulting in a higher purity.

[0107] Furthermore, the timing of the second heat treatment is not particularly limited as long as it occurs after the formation of the oxide semiconductor film 206. No. For example, a second heat treatment may be performed after the formation of the gate electrode 214. Or, After the first heat treatment, the second heat treatment may be performed, or the second heat treatment may be combined with the first heat treatment, or the first heat treatment may be combined with the second heat treatment. That is, the second heat treatment may be included in the first heat treatment, or the first heat treatment may be included in the second heat treatment.

[0108] As described above, by applying at least one of the first heat treatment and the second heat treatment, the oxide semiconductor film 206 can be purified to a high purity so that it contains as few impurities as possible other than its main components. In the highly purified oxide semiconductor film 206, carriers derived from donors are extremely few (close to zero), and the carrier concentration is less than 1×10 / cm , preferably less than 1×1 14 / cm 3 , more preferably less than 1×10 0 12 / cm 3 , and even more preferably less than 1×10 11 / cm 3 .

[0109] Thereafter, a gate electrode 214 is formed (see FIG. 4(E)). The gate electrode 214 can be formed using a metal material such as molybdenum, titanium, tantalum, tungsten, aluminum, copper, neodymium, scandium, or an alloy material containing these as main components. Note that the gate electrode 214 may have a single-layer structure or a stacked structure. [[ID=三十四]]That is, the gate electrode 214 may have a single-layer structure or a stacked structure. The transistor 110 is formed in the above steps.

[0110] [[ID=四十一]] [[ID=四十二]]

[0111] [[ID=四十三]] <〈Manufacturing process of transistor 120〉 An example of the manufacturing process of the transistor 120 shown in FIG. 3(A) will be described using FIGS. 5(A) to 5(E). Note that the manufacturing process of the transistor 160 shown in FIG. 3(E) is the same as the manufacturing process of the transistor 120, except that the second metal oxide film 210 is processed according to the shape of the oxide semiconductor film 206. <00s0810>

[0112] ​​​​ First, an insulating film 202 is formed on the substrate 200, and the first is placed in contact with the insulating film 202. A metal oxide film 204 is formed (see Figure 5(A)). For details, see transistor 11. The description regarding the manufacturing process of 0 can be consulted.

[0113] Next, on the first metal oxide film 204, the source electrode and drain electrode (in the same layer) are placed. A conductive film is formed to form wiring (including that which is formed by), and the conductive film is processed to form a so Form the drain electrode 208a and drain electrode 208b (see Figure 5(B)). Therefore, we can refer to the description regarding the manufacturing process of transistor 110.

[0114] Next, source electrode 208a and drain electrode 208 are placed on the first metal oxide film 204. An oxide semiconductor film is formed to connect to b, and the oxide semiconductor film is processed to create island-shaped oxide semiconductors. A body membrane 206 is formed (see Figure 5(C)). For details, see Fabrication of Transistor 110. The description of the process can be taken into consideration.

[0115] Next, the source electrode 208a and the drain electrode 208b are covered, and an oxide semiconductor film is formed. A second metal oxide film 210 is formed so as to be in contact with a portion of 206, and then the second metal A gate insulating film 212 is formed so as to be in contact with the oxide film 210 (see Figure 5(D)). For further details, refer to the description of the manufacturing process for transistor 110.

[0116] Subsequently, the gate electrode 214 is formed (see Figure 5(E)). For details, see Transition You can refer to the description regarding the manufacturing process of Sta 110.

[0117] The transistor 120 is formed through the above process.

[0118] The transistor according to this embodiment has an oxide semiconductor film on the upper and lower surfaces, A metal oxide film made of the same components as the semiconductor film is stacked, and furthermore, acid is applied to the metal oxide film. The surface in contact with the oxide semiconductor film and the surface facing it have different properties than the metal oxide film and the oxide semiconductor film. An insulating film made of the same component is provided in contact with it. By having a metal oxide film composed of a material in contact with an oxide semiconductor film, Charges that may be generated due to the operation of semiconductor devices, etc., between the oxide semiconductor film and the metal oxide film. A material is used that suppresses trapping at the interface and further allows charge trapping centers to be formed at the interface. By having an insulator composed of such materials in contact with a metal oxide film, the metal oxide The aforementioned charges can be trapped at the interface between the film and the insulator. This allows oxide semiconductors to... Because it can mitigate the effects of charge on the body membrane, it can trap charge at the oxide semiconductor film interface. This can suppress transistor threshold fluctuations caused by [the aforementioned factor].

[0119] Furthermore, the oxide semiconductor film used in the active layer of the transistor undergoes heat treatment, which removes hydrogen and moisture. By removing impurities such as hydroxyl groups or hydrides (also called hydrogen compounds) from oxide semiconductors. Furthermore, the main component material constituting the oxide semiconductor is simultaneously reduced by the impurity removal process. By supplying oxygen, which is a material, the oxide semiconductor film is purified and electrically converted to type i. It is a (true) purified product. Transigs containing such highly purified oxide semiconductor films The device exhibits suppressed electrical characteristic fluctuations and is electrically stable.

[0120] Furthermore, when charge is trapped at the interface of an oxide semiconductor film, the threshold voltage of the transistor is affected. It shifts (for example, if a positive charge is trapped on the back channel side, the transistor The threshold voltage shifts in the negative direction, but one of the factors causing this charge trapping is positive We can assume a model of the movement and trapping of ON (or the atom causing it). And in transistors using oxide semiconductors, such a cation source is Hydrogen atoms are a possibility. The disclosed invention uses a highly purified oxide semiconductor, and also, Because this employs a configuration in which the metal oxide film and insulating film are in contact with each other, the above model Even charge trapping caused by hydrogen, which is anticipated in the case of , can be suppressed. The model is thought to be valid even if the ionization rate of hydrogen is, for example, around 10%.

[0121] As described above, we provide a semiconductor device using an oxide semiconductor with stable electrical characteristics. This allows us to provide highly reliable semiconductor devices.

[0122] The configurations and methods described in this embodiment are similar to those described in other embodiments. They can be used in combination as appropriate.

[0123] (Embodiment 2) A semiconductor device (display device) having a display function using the transistor exemplified in Embodiment 1. It is also possible to manufacture (also known as) a part or all of a drive circuit including a transistor. The entire body can be integrally formed on the same substrate as the pixel section, thereby forming a system-on-panel.

[0124] In Figure 6(A), surrounding the pixel portion 4002 provided on the first substrate 4001 A sealing material 4005 is provided and sealed by the second substrate 4006. Figure 6 In (A), in a region surrounded by a sealing material 4005 on a first substrate 4001 In a region different from this, a scanning line drive circuit 4004 and a signal line drive circuit 4003 formed of a single crystal semiconductor film or a polycrystalline semiconductor film on a separately prepared substrate are mounted. Also, separately The formed signal line drive circuit 4003 and various signals and potentials supplied to the scanning line drive circuit 4004 or the pixel portion 4002 are supplied from FPC (Flexible printed cir cuit) 4018a and FPC 4018b.

[0125] In FIGS. 6(B) and 6(C), a sealing material 4005 is provided so as to surround the pixel portion 40 02 provided on the first substrate 4001 and the scanning line drive circuit 4004. Also, a second substrate 4006 is provided on the pixel portion 4002 and the scanning line drive circuit 4004 Thus, the pixel portion 4002 and the scanning line drive circuit 4004 are sealed together with the display element by the first substrate 400 1, the sealing material 4005, and the second substrate 4006. In FIGS. 6(B) and 6(C), in a region different from the region surrounded by the sealing material 4005 on the first substrate 4001, a signal line drive circuit 4003 formed of a single crystal semiconductor film or a polycrystalline semiconductor film on a separately prepared substrate is mounted. In FIGS. 6(B) and 6(C), various signals and potentials supplied to the separately formed signal line drive circuit 4003 and the scanning line drive circuit 4004 or the pixel portion 4002 are supplied from FPC 4018.

[0126] Also, in FIGS. 6(B) and 6(C), an example in which the signal line drive circuit 4003 is separately formed and mounted on the first substrate 4001 is shown, but the configuration is not limited to this. Scanning Alternatively, a separate line drive circuit may be formed and implemented, or it may be part of the signal line drive circuit or the scan line drive circuit. It is also acceptable to separately form and implement only a portion of the path.

[0127] Furthermore, the method of connecting the separately formed drive circuit is not particularly limited, and COG(C (hip-on-glass) method, wire bonding method, or TAB (Tape) Automated bonding methods can be used. Figure 6(A) shows This is an example of implementing the signal line drive circuit 4003 and the scan line drive circuit 4004 using the COG method. Figure 6(B) shows an example of implementing the signal line drive circuit 4003 using the COG method, and Figure 6( C) is an example of implementing the signal line drive circuit 4003 using the TAB method.

[0128] Furthermore, the display device includes a panel in which the display elements are sealed, and a control on the panel This includes modules that have ICs, etc., mounted on them, including those containing R.

[0129] In this specification, the term "display device" refers to an image display device, a display device, or This refers to light sources (including lighting devices). It also includes connectors, such as FPC or TAB tapes. Alternatively, a module with TCP attached, or a printed circuit board at the end of a TAB tape or TCP. A module or display element equipped with a COG (Center of Gravity) is directly implemented with an IC (integrated circuit) using the COG method. All installed modules shall also be included in the display device.

[0130] Furthermore, the pixel section and scan line driving circuit provided on the first substrate use multiple transistors. It possesses such a feature, and the transistor shown as an example in Embodiment 1 can be applied.

[0131] Display elements provided in a display device include liquid crystal elements (also called liquid crystal display elements) and light-emitting elements. A light-emitting element (also called a light-emitting display element) can be used. The light-emitting element is activated by current or voltage. This category includes elements whose brightness is controlled by [something], specifically inorganic EL (Electroluminescent) elements. This includes Luminescence, organic EL, etc. Also, electronic inks, etc. Display media whose contrast changes due to the effect can also be used.

[0132] One form of a semiconductor device will be described using Figures 7 to 9. Figures 7 to 9 are the same as those in Figure 6. This corresponds to the cross-sectional view in MN of (B).

[0133] As shown in Figures 7 to 9, the semiconductor device has a connecting terminal electrode 4015 and a terminal electrode 401 It has 6, and the connecting terminal electrode 4015 and terminal electrode 4016 are located in FPC4018 It is electrically connected to the terminal via an anisotropic conductive film 4019.

[0134] The connecting terminal electrode 4015 is formed from the same conductive film as the first electrode layer 4030, and the terminal electrode 4016 is the source electrode and drain of transistors 4010 and 4011. It is formed from the same conductive film as the electrodes.

[0135] Furthermore, there is a pixel section 4002 provided on the first substrate 4001 and a scanning line driving circuit 4004 It has multiple transistors, and in Figures 7 to 9, the transistors included in the pixel section 4002 Transistor 4010 and transistor 4011 included in the scan line drive circuit 4004 are shown as examples. They are doing it.

[0136] In this embodiment, transistors 4010 and 4011 are defined as follows: The transistor shown in 1 can be applied. Transistors 4010 and transitor 4011 have suppressed electrical characteristic variations and are electrically stable. Therefore, it is possible to provide a highly reliable semiconductor device as the semiconductor device of the present embodiment shown in FIGS. 7 to FIG. 9.

[0137] The transistor 4010 provided in the pixel portion 4002 is electrically connected to the display element and constitutes a display panel. The display element is not particularly limited as long as it can perform display, and various display elements can be used.

[0138] FIG. 7 shows an example of a liquid crystal display device using a liquid crystal element as a display element. In FIG. 7, the liquid crystal element 4013, which is the display element, includes a first electrode layer 4030, a second electrode layer 4031, and a liquid crystal layer 4008. Insulating films 4032 and 4033 that function as alignment films are provided so as to sandwich the liquid crystal layer 4008. The second electrode layer 4031 is provided on the second substrate 4 006 side, and the first electrode layer 4030 and the second electrode layer 4031 are stacked via the liquid crystal layer 4008 in a configuration.

[0139] Also, the columnar spacer 4035 is obtained by selectively etching an insulating film and is provided to control the film thickness (cell gap) of the liquid crystal layer 4008. Note that a spherical spacer may be used.

[0140] When a liquid crystal element is used as the display element, thermotropic liquid crystal, low molecular liquid crystal, high molecular liquid crystal, polymer dispersed liquid crystal, ferroelectric liquid crystal, antiferroelectric liquid crystal, etc. can be used. These liquid crystal materials may be in a cholesteric phase, a smectic phase, a cubic phase, a ca ​​​It exhibits iralnematic phase, isotropic phase, etc.

[0141] Alternatively, a liquid crystal exhibiting a blue phase without an alignment layer may be used. The blue phase is one of the liquid crystal phases. Therefore, as the temperature of a cholesteric liquid crystal is increased, it transitions from the cholesteric phase to the isotropic phase. This is the phase that appears immediately before. The blue phase only appears within a narrow temperature range, so the temperature range needs to be modified. To improve performance, a liquid crystal composition containing several weight percent or more of a chiral agent is used in the liquid crystal layer. A liquid crystal composition containing a liquid crystal exhibiting a blue phase and a chiral agent has a response speed of 1 msec or less. Because it is short and optically isotropic, orientation processing is unnecessary and it has low dependence on the viewing angle. Since a targeting film does not need to be applied, rubbing treatment is also unnecessary, and therefore the rubbing treatment does not affect the adhesion. This prevents electrostatic discharge (ESD) damage and minimizes defects and damage to liquid crystal displays during the manufacturing process. This can be reduced. Therefore, it becomes possible to improve the productivity of liquid crystal display devices.

[0142] Furthermore, the resistivity of liquid crystal materials is 1 × 10⁻⁶ 9 The value is Ω·cm or greater, preferably 1 × 10⁻⁶. 11 It is Ω·cm or greater, and more preferably 1 × 10⁻⁶ 12 It is greater than Ω·cm. The resistivity values ​​in the specification shall be those measured at 20°C.

[0143] The size of the retention capacitance provided in a liquid crystal display device depends on the number of transistors arranged in the pixel area. The charge is maintained for a predetermined period, taking into account factors such as the current. High-purity oxidation By using a transistor having a physical semiconductor film, the liquid crystal capacitance in each pixel is It is sufficient to provide a holding capacity having a size of 1 / 3 or less, preferably 1 / 5 or less of the capacity. ru.

[0144] The transistor using the highly purified oxide semiconductor film used in this embodiment is in the off state. The current value in the state (off-current value) can be reduced. Therefore, electrical signals such as image signals can be reduced. The number retention time can be extended, and the write interval can also be set to be longer when the power is on. Therefore, the frequency of refresh operations can be reduced, thus effectively suppressing power consumption. It will bear fruit.

[0145] Furthermore, the transistor using the highly purified oxide semiconductor film used in this embodiment is Because a relatively high field-effect mobility can be obtained, high-speed driving is possible. Therefore, liquid crystal display equipment By using the above-mentioned transistors in the pixel section, high-quality images can be provided. Furthermore, the above transistors are manufactured on the same substrate, either in the drive circuit section or the pixel section. This allows for a reduction in the number of components in a liquid crystal display device.

[0146] LCD displays include TN (Twisted Nematic) mode and IPS (In- Plane-Switching) mode, FFS (Fringe Field Switching) tching) mode, ASM(Axially Symmetric aligned) Micro-cell) mode, OCB(Optical Compensated) Birefringence mode, FLC (Ferroelectric Liqu id Crystal) mode, AFLC (AntiFerroelectric Li) You can use modes such as Quid Crystal.

[0147] Furthermore, a normally black type liquid crystal display device, for example, one that employs vertical alignment (VA) mode, It may also be a transmissive liquid crystal display device. Here, the vertical alignment mode refers to the liquid crystal display panel This is a type of method for controlling the arrangement of liquid crystal molecules, and when no voltage is applied, the panel surface... In contrast, this is a method in which liquid crystal molecules are oriented vertically. Several vertical orientation modes can be listed. However, for example, MVA (Multi-domain Vertical Alignment) ent) mode, PVA (Patterned Vertical Alignment) Use modes such as ) mode, ASV (Advanced Super View) mode, etc. This is possible. Also, a pixel can be divided into several regions (subpixels), and each Multi-domainization or multi-domain design is a method that involves tilting molecules in a different direction. The method known as can be used.

[0148] Furthermore, in a display device, a black matrix (light-shielding layer), a polarizing member, a phase difference member, and a reverse Optical components (optical substrates) such as anti-radiation members may be provided as appropriate. For example, polarizing substrates and phase Circular polarization using a differential substrate may also be used. Furthermore, backlights, sidelights, etc., can be used as light sources. You may also use [this].

[0149] Furthermore, multiple light-emitting diodes (LEDs) are used as backlights, and a time-division display method is used. It is also possible to perform the (field sequential drive method). By applying a scalar drive method, color display is achieved without using a color filter. It is possible.

[0150] Furthermore, the display method used in the pixel area may be a progressive or interlaced method. It is possible to do so. Also, the color elements controlled by pixels when displaying color include RGB(R It is not limited to the three colors (where G represents red, G represents green, and B represents blue). For example, RGBW (where W represents white). ), or RGB with one or more additional colors such as yellow, cyan, magenta, etc. The size of the display area may differ for each dot of the color element. However, this invention This is not limited to color display devices, but can also be applied to monochrome display devices. It can also be done this way.

[0151] Furthermore, the display element included in the display device utilizes light emission that employs electroluminescence. Elements can be applied. Light-emitting devices that utilize electroluminescence are light-emitting materials They are distinguished by whether the substance is an organic compound or an inorganic compound; generally, the former is organic EL elements, and the latter are called inorganic EL elements.

[0152] Organic EL elements emit electrons and positive voltages from a pair of electrodes when a voltage is applied to the light-emitting element. Each pore is injected into a layer containing a luminescent organic compound, and an electric current flows through it. The recombination of carriers (electrons and holes) causes the luminescent organic compound to form an excited state. It then emits light when the excited state returns to the ground state. From this mechanism, These light-emitting elements are called current-excited light-emitting elements.

[0153] Inorganic EL elements are classified into dispersed inorganic EL elements and thin-film inorganic EL elements depending on their element configuration. It is classified as follows: Dispersed inorganic EL elements have a light-emitting layer in which particles of light-emitting material are dispersed in a binder. It possesses a donor-acceptor level, and the luminescence mechanism utilizes donor-acceptor levels. This is acceptor-recombination type light emission. Thin-film inorganic EL elements sandwich the light-emitting layer between dielectric layers. Furthermore, it has a structure where it is sandwiched between electrodes, and the light emission mechanism involves the inner-shell electron transition of metal ions. The localized light emission method used is localized light emission. For this explanation, an organic EL element is used as the light-emitting element. do.

[0154] A light-emitting element only needs to have at least one of its pair of electrodes transparent in order to extract light. Then, a transistor and a light-emitting element are formed on the substrate, and light is emitted from the side opposite to the substrate. This includes top-side emission, bottom-side emission which extracts light from the substrate side, and both the substrate side and the opposite side of the substrate. There are light-emitting elements with a double-sided emission structure that extract light from the side surface, and any light-emitting element with an emission structure is suitable It can be used.

[0155] Figure 8 shows an example of a light-emitting device using a light-emitting element as a display element. 4513 is electrically connected to transistor 4010 located in pixel section 4002. The configuration of the light-emitting element 4513 is a first electrode layer 4030, an electroluminescent layer 4511, and a second The electrode layer 4031 has a stacked structure, but is not limited to the configuration shown. The configuration of the light-emitting element 4513 can be appropriately changed to match the direction of the light being extracted. .

[0156] The partition wall 4510 is formed using an organic insulating material or an inorganic insulating material. In particular, photosensitive Using a resin material, an opening is formed on the first electrode layer 4030, and the side walls of the opening are continuous. It is preferable to form the inclined surface with a curvature.

[0157] Even if the electroluminescent layer 4511 consists of a single layer, it is configured to be stacked with multiple layers. It doesn't matter whether it's done or not.

[0158] To prevent oxygen, hydrogen, moisture, carbon dioxide, etc. from entering the light-emitting element 4513, the second electrode A protective film may be formed on layer 4031 and partition wall 4510. As the protective film, silica nitride Condenser film, silicon nitride film, DLC (Diamond-Like Carbon) film, etc. It is possible to form a first substrate 4001, a second substrate 4006, and a sheet. The space sealed by material 4005 is filled with filler material 4514 and sealed. A protective film (laminate) that is highly airtight and has minimal degassing, so as not to be exposed to the outside air. Packaging (enclosing) with a film, UV-curing resin film, etc. or a cover material. It is preferable.

[0159] In addition to inert gases such as nitrogen and argon, filler material 4514 can also be UV-curing resin. Alternatively, thermosetting resins can be used, such as PVC (polyvinyl chloride), acrylic, and poly Imide, epoxy resin, silicone resin, PVB (polyvinyl butyral) or EVA ( Ethylene vinyl acetate can be used. For example, if nitrogen is used as a filler... good.

[0160] Additionally, if necessary, a polarizing plate or circular polarizing plate (including elliptical polarizing plates) may be placed on the emission surface of the light-emitting element. ), phase difference plates (λ / 4 plate, λ / 2 plate), color filters, and other optical films are appropriately provided. Alternatively, an anti-reflective coating may be provided on the polarizing plate or circular polarizing plate. For example, surface irregularities This allows for an anti-glare treatment that diffuses reflected light and reduces glare.

[0161] Furthermore, it is also possible to provide electronic paper that drives electronic ink as a display device. Yes, there is. Electronic paper is also called an electrophoretic display device (electrophoretic display), It is possible to achieve the same readability as paper, lower power consumption compared to other display devices, and a thin and light form factor. It has the advantage of being such.

[0162] Electrophoresis display devices can take various forms, but they typically involve detecting a first particle with a positive charge. A microcapsule containing a second particle having a negative charge is mixed with a solvent or solute. It is dispersed in several parts, and by applying an electric field to the microcapsules, the microcapsules Move the particles in the capsule in opposite directions and display only the color of the particles that have gathered on one side. This is the case. Furthermore, the first or second particle contains dye, and in the absence of an electric field. It does not move. Also, the color of the first particle and the color of the second particle are different (including colorless). (to do).

[0163] Thus, electrophoretic devices detect the movement of substances with high dielectric constants into high electric field regions. This is a display that utilizes the so-called dielectrophoretic effect.

[0164] When the above microcapsules are dispersed in a solvent, it is called an electronic ink. This electronic ink can be printed on surfaces such as glass, plastic, fabric, and paper. Furthermore, color display is possible by using color filters or particles containing pigments.

[0165] The first and second particles in the microcapsules are made of conductive material and insulating material. Semiconductor materials, magnetic materials, liquid crystal materials, ferroelectric materials, electroluminescent materials, A type of material selected from chromochromic materials, magnetophoretic materials, or a composite of these materials. You can use it.

[0166] Furthermore, a display device using a twist-ball display method will also be applied as an electronic paper. This is possible. The twist ball display method uses spherical particles painted in white and black as display elements. It is placed between the first electrode layer and the second electrode layer, which are the electrode layers to be used, and the first electrode layer and By generating a potential difference in the second electrode layer and controlling the orientation of the spherical particles, the display is performed. It is the law.

[0167] Figure 9 shows an active-matrix electronic paper as one form of semiconductor device. Electronic paper 9 is an example of a display device that uses a twist-ball display method.

[0168] A first electrode layer 4030 connected to the transistor 4010, and provided on the second substrate 4006 Between the second electrode layer 4031 and the black region 4615a and the white region 4615b are provided. A spherical particle 4613 is provided, which has a cavity 4612 that is filled with liquid around it. The spherical particles 4613 are surrounded by a filler material 4614 such as resin. The electrode layer 4031 corresponds to the common electrode (counter electrode). The second electrode layer 4031 is at a common potential. It is electrically connected to the wire.

[0169] In Figures 7 to 9, the first substrate 4001 and the second substrate 4006 are, In addition to lath substrates, flexible substrates can also be used, for example, translucent plastic substrates. A plastic substrate such as a vinyl substrate can be used. As for plastics, FRP (Fiber Reinforced Plastic) can be used. Ass-Reinforced Plastics) board, PVF (Polyvinyl Fiber) (D) Film, polyester film, or acrylic resin film can be used. Also, a structure in which aluminum foil is sandwiched between PVF film or polyester film. You can also use the 'te' symbol.

[0170] The insulating layer 4021 can be formed using an inorganic insulating material or an organic insulating material. Furthermore, acrylic resin, polyimide, benzocyclobutene resin, polyamide, epoxy resin When using heat-resistant organic insulating materials such as the above, they are suitable as planar insulating films. In addition to the above organic insulating materials, low dielectric constant materials (low-k materials), siloxane resins, PSG (Phosphorus glass), BPSG (Phosphorus Boron glass), etc. can be used. An insulating layer may be formed by stacking multiple insulating films made of the aforementioned material.

[0171] The method for forming the insulating layer 4021 is not particularly limited and may vary depending on the material, such as sputtering. Spin coating, dipping, spray coating, droplet ejection (inkjet method, spray Lean printing, offset printing, etc. can be applied. Roll coating, car The insulating layer 4021 can also be formed using a tensile coating, knife coating, etc. ru.

[0172] A display device displays information by transmitting light from a light source or display element. Therefore, light is transmitted. Thin films such as substrates, insulating films, and conductive films provided in the pixel area all emit light in the visible light wavelength range. It is made to be translucent.

[0173] A first electrode layer and a second electrode layer (pixel electrode layer, common electrode layer) that apply voltage to the display element. In the counter electrode layer (also called the counter electrode layer), the direction of the light to be extracted, the location where the electrode layer is provided, Transmittance and reflectivity can be selected based on the pattern structure of the electrode layer.

[0174] The first electrode layer 4030 and the second electrode layer 4031 are made of indium containing tungsten oxide. Indium zinc oxide containing oxides, tungsten oxide, and indium acid containing titanium oxide Indium tin oxide containing titanium oxide, indium tin oxide (hereinafter referred to as ITO) . ) The light transmittance of indium zinc oxide, silicon oxide-added indium tin oxide, etc. A conductive material can be used.

[0175] Furthermore, the first electrode layer 4030 and the second electrode layer 4031 are made of tungsten (W) and molybdenum. N (Mo), Zirconium (Zr), Hafnium (Hf), Vanadium (V), Niobium ( Nb), tantalum (Ta), chromium (Cr), cobalt (Co), nickel (Ni), chromium (Cr), cobalt (Co), nickel (Ni), chromium (Cr), cobalt (Co), cobalt (Co), cobalt (Ni), cobalt (Co Metals such as tungsten (Ti), platinum (Pt), aluminum (Al), copper (Cu), and silver (Ag). or formed using one or more of the alloy or nitride thereof. can.

[0176] Furthermore, the first electrode layer 4030 and the second electrode layer 4031 are made of conductive polymer (conductive polymer It can be formed using a conductive composition containing a conductive polymer (also called a rimer). Therefore, so-called π-electron conjugated conductive polymers can be used. For example, polyaniline or its derivatives, polypyrrole or its derivatives, polythiophene or its derivatives, or a copolymer consisting of two or more of aniline, pyrrole and thiophene or the Examples include derivatives.

[0177] Furthermore, transistors are susceptible to damage from static electricity, etc., so a protective circuit is needed to protect the drive circuit. It is preferable to provide a path. The protection circuit is preferably constructed using nonlinear elements.

[0178] As described above, by applying the transistor exemplified in Embodiment 1, a highly reliable semiconductor can be obtained. A conductive device can be provided. The transistor exemplified in Embodiment 1 is as described above. This includes not only semiconductor devices with display functions, but also power devices and LSIs mounted in power supply circuits. Semiconductor integrated circuits such as semiconductors, semiconductor devices with image sensor functions for reading information about objects, etc. It can be applied to semiconductor devices with a variety of functions.

[0179] The configurations and methods described in this embodiment are similar to those described in other embodiments. They can be used in combination as appropriate.

[0180] (Embodiment 3) The semiconductor devices disclosed herein are applicable to a variety of electronic devices (including gaming machines). This can be done. As for electronic devices, for example, television equipment (television, or television) (Also called a receiver), computer monitors, digital cameras, digital video cameras Cameras such as Mera, digital photo frames, mobile phones (also known as mobile phones or mobile phone devices) (u) Portable game consoles, personal information terminals, sound playback devices, and large game machines such as pachinko machines. Examples include the above. Regarding the example of an electronic device equipped with a liquid crystal display device as described in the above embodiment, I will explain.

[0181] Figure 10(A) shows a notebook-type personal computer, consisting of a main unit 3001 and a casing 30 It consists of 02, a display unit 3003, a keyboard 3004, etc. Embodiment 1 Alternatively, by applying the semiconductor device shown in Embodiment 2, a highly reliable notebook-type It can be used as a personal computer.

[0182] Figure 10(B) shows a personal digital assistant (PDA), and the main unit 3021 has a display unit 3023 and An external interface 3025 and operation buttons 3024 are provided. A stylus 3022 is provided as an accessory for operation. As shown in Embodiment 1 or Embodiment 2. By applying semiconductor devices, it is possible to create more reliable personal digital assistants (PDAs). It is possible.

[0183] Figure 10(C) shows an example of an e-book. For example, e-book 2700 has a housing 2 It consists of two enclosures, 701 and enclosure 2703. Enclosure 2701 and enclosure 27 03 is integrated with the shaft portion 2711, and the shaft portion 2711 is used as the axis for opening and closing operations. This configuration makes it possible to perform actions similar to those of a paper book. .

[0184] The display unit 2705 is incorporated into the housing 2701, and the display unit 2707 is incorporated into the housing 2703. It is included. Display units 2705 and 2707 are configured to display a continuation screen. Alternatively, a configuration that displays different screens is also acceptable. For example, text is displayed on the right-hand display unit (display unit 2705 in Figure 10(C)), and on the left... An image can be displayed on the display unit (display unit 2707 in Figure 10(C)). By applying the semiconductor device shown in Embodiment 1 or Embodiment 2, a highly reliable electronic book The registration number can be set to 2700.

[0185] Furthermore, Figure 10(C) shows an example in which the housing 2701 is equipped with an operating section, etc. For example In the enclosure 2701, the power supply 2721, operation keys 2723, speaker 2725, etc. It is equipped with this feature. Pages can be turned using operation key 2723. Note that the display unit of the casing is the same as the display unit. The configuration may also include a keyboard and pointing device on one side. On the back or sides, there are external connection terminals (earphone terminal, USB terminal, etc.) and a recording medium insertion slot. It may also be configured to include such features. Furthermore, the eBook 2700 has the functionality of an electronic dictionary. It can also be configured in a way that allows it to stand still.

[0186] Furthermore, the e-book 2700 may be configured to transmit and receive information wirelessly. The system will be configured to purchase and download desired book data from an e-book server. It is also possible.

[0187] Figure 10(D) shows a mobile phone, which consists of two housings, housing 2800 and housing 2801. It has been done. The enclosure 2801 contains a display panel 2802, a speaker 2803, and a micro Phone 2804, pointing device 2806, camera lens 2807, external connection It is equipped with terminal 2808, etc. Furthermore, the housing 2800 is used for charging portable information terminals. It is equipped with a solar cell 2810, an external memory slot 2811, and other features. It is built into the housing 2801. The semiconductor shown in Embodiment 1 or Embodiment 2. By applying this device, a highly reliable mobile phone can be created.

[0188] Furthermore, the display panel 2802 is equipped with a touch panel, and Figure 10(D) shows video display. The multiple operation keys 2805 are shown with dotted lines. Note that the solar cell 2810 A boost circuit is also implemented to increase the applied voltage to the voltage required for each circuit.

[0189] The display panel 2802 changes its orientation as appropriate depending on the usage mode. Since the camera lens 2807 is mounted on the same plane as the 2802, video calls are possible. Yes. Speaker 2803 and microphone 2804 are not limited to voice calls, but also television broadcasts. It is capable of speaking, recording, and playing back. Furthermore, the casings 2800 and 2801 slide apart. As shown in Figure 10(D), it can be changed from an unfolded state to an overlapping state, and it can be carried. It can be miniaturized to suit various applications.

[0190] External connection terminal 2808 connects to various cables such as AC adapters and USB cables. It is possible, and it can be charged and communicate with personal computers and other devices. By inserting a recording medium into the external memory slot 2811, you can store and move larger amounts of data. We can handle it.

[0191] Furthermore, in addition to the above functions, it is equipped with infrared communication functions, television reception functions, etc. That's good too.

[0192] Figure 10(E) shows a digital video camera, consisting of a main unit 3051 and a display unit (A) 3057. Eyepiece 3053, operation switch 3054, display unit (B) 3055, battery 3056 It is composed of the above. The semiconductor device shown in Embodiment 1 or Embodiment 2 is suitable By using this, a highly reliable digital video camera can be created.

[0193] Figure 10(F) shows an example of a television system. The television system 9600 is The display unit 9603 is incorporated into the housing 9601. The display unit 9603 displays images. It is possible to demonstrate this. Furthermore, here, the stand 9605 supports the housing 9601. The configuration shown is applied to the semiconductor device shown in Embodiment 1 or Embodiment 2. This makes it possible to create a highly reliable television system.

[0194] The television unit 9600 is operated using the control switches on the housing 9601, as well as a separate unit. This can be done using the remote control unit. Alternatively, the remote control unit can be connected to the remote control unit. The system may also be configured to include a display unit that shows the output information.

[0195] The television system 9600 will consist of a receiver, modem, and other components. This allows for the reception of regular television broadcasts, and furthermore, wired or wireless connections are available via the modem. By connecting to a communication network, one-way (sender to receiver) or two-way communication is possible. It is also possible to perform two-way information communication (between a sender and receiver, or between receivers, etc.). .

[0196] The configurations and methods described in this embodiment are similar to those described in other embodiments. They can be used in combination as appropriate. [Explanation of Symbols]

[0197] 110 transistors 120 transistors 130 transistors 140 transistors 150 transistors 160 transistors 170 transistors 180 transistors 200 circuit boards 202 Insulating film 204 Metal oxide film 206 oxide semiconductor film 208a Source electrode 208b Drain electrode 210 Metal oxide film 212 Gate Insulator 214 Grid gate 2700 eBooks 2701 enclosure 2703 Casing 2705 ​​Display section 2707 Display section 2711 Shaft 2721 Power supply 2723 Operation Keys 2725 Speakers 2800 cabinets 2801 enclosure 2802 Display Panel 2803 Speaker 2804 Microphone 2805 Operation Keys 2806 Pointing device 2807 Camera Lens 2808 External connection terminal 2810 solar cells 2811 External memory slot 3001 Main Unit 3002 enclosure 3003 Display section 3004 Keyboard 3021 Main Unit 3022 Stylus 3023 Display section 3024 Operation Buttons 3025 External Interface 3051 Main Unit 3053 Eyepiece 3054 Operation switch 3055 Display section (B) 3056 Battery 3057 Display section (A) 4001 circuit board 4002 pixel section 4003 Signal Line Drive Circuit 4004 Scan Line Drive Circuit 4005 Sealant 4006 circuit board 4008 Liquid Crystal Layer 4010 Transistor 4011 Transistor 4013 Liquid crystal element 4015 Connection terminal electrode 4016 Terminal electrode 4018 FPC 4018a FPC 4018b FPC 4019 Anisotropic conductive film 4021 Insulating layer 4030 Electrode layer 4031 Electrode layer 4032 Insulating film 4033 Insulating film 4035 Spacer 4510 Bulkhead 4511 Electroluminescent layer 4513 Light-emitting element 4514 Filling material 4612 Cavity 4613 Spherical particles 4614 Filling material 4615a Black area 4615b White area 9600 Television equipment 9601 enclosure 9603 Display section 9605 Stand

Claims

1. The first oxide film and A first conductive film having a region on the first oxide film, A second conductive film having a region on the first oxide film, An oxide semiconductor film having a region on the first oxide film, A second oxide film having a region on the oxide semiconductor film, A third conductive film having a region on the second oxide film, The second oxide film has the same material as the first oxide film, The oxide semiconductor film has a channel formation region for the transistor, The first conductive film functions as either the source electrode or the drain electrode of the transistor. The second conductive film functions as either the source electrode or the drain electrode of the transistor. The third conductive film has the function of a gate electrode of the transistor. The second oxide film has a region in contact with the upper surface of the oxide semiconductor film, The oxide semiconductor film has a region in contact with the upper surface of the first oxide film, The oxide semiconductor film has a region in contact with the upper surface of the first conductive film and a region in contact with the side surface of the first conductive film. The oxide semiconductor film has a region in contact with the upper surface of the second conductive film and a region in contact with the side surface of the second conductive film. The third conductive film has a region that overlaps with the oxide semiconductor film via the second oxide film. The second oxide film has a region that does not overlap with the third conductive film. The first conductive film has a region that does not overlap with the second oxide film. The second conductive film has a region that does not overlap with the second oxide film. In a cross-sectional view of the cross-section obtained by cutting along the channel length direction of the transistor, the end of the second oxide film is positioned above the oxide semiconductor film. The thickness of the first oxide film is greater than the thickness of the oxide semiconductor film. A semiconductor device wherein the thickness of the second oxide film is greater than the thickness of the oxide semiconductor film.

2. The first oxide film and A first conductive film having a region on the first oxide film, A second conductive film having a region on the first oxide film, An oxide semiconductor film having a region on the first oxide film, A second oxide film having a region on the oxide semiconductor film, A third conductive film having a region on the second oxide film, The second oxide film has the same material as the first oxide film, The oxide semiconductor film has a channel formation region for the transistor, The first conductive film functions as either the source electrode or the drain electrode of the transistor. The second conductive film functions as either the source electrode or the drain electrode of the transistor. The third conductive film has the function of a gate electrode of the transistor. The second oxide film has a region in contact with the upper surface of the oxide semiconductor film, The oxide semiconductor film has a region in contact with the upper surface of the first oxide film, The oxide semiconductor film has a region in contact with the upper surface of the first conductive film and a region in contact with the side surface of the first conductive film. The oxide semiconductor film has a region in contact with the upper surface of the second conductive film and a region in contact with the side surface of the second conductive film. The third conductive film has a region that overlaps with the oxide semiconductor film via the second oxide film. The second oxide film has a region that does not overlap with the third conductive film. The first conductive film has a region that does not overlap with the second oxide film. The second conductive film has a region that does not overlap with the second oxide film. In a cross-sectional view of the transistor cut along the channel length direction, the end of the second oxide film is positioned above the oxide semiconductor film, and the end of the third conductive film is positioned above the second oxide film. The thickness of the first oxide film is greater than the thickness of the oxide semiconductor film. A semiconductor device wherein the thickness of the second oxide film is greater than the thickness of the oxide semiconductor film.

3. In claim 1 or claim 2, The first conductive film has a region that overlaps with the oxide semiconductor film and a region that does not overlap with the oxide semiconductor film. The semiconductor device comprises a second conductive film having a region that overlaps with the oxide semiconductor film and a region that does not overlap with the oxide semiconductor film.

Images